Fitbit MCP Server

get_azm_timeseries

Retrieve Active Zone Minutes time series data from Fitbit, including total and breakdown by fat burn, cardio, and peak zones, over a specified date range.

Instructions

Get the raw JSON response for Active Zone Minutes (AZM) time series data from Fitbit over a date range (max 1095 days). Returns total AZM plus breakdown by fat burn, cardio, and peak zones.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "startDate": "<startDate>",
      "endDate": "<endDate>"
    },
    "name": "get_azm_timeseries"
  }
}

Input Schema

Name	Required	Description	Default
`startDate`	Yes	The start date for which to retrieve data (YYYY-MM-DD)
`endDate`	Yes	The end date for which to retrieve data (YYYY-MM-DD)

Schema Changelog

Changes observed during successful MCP inspections.

Addedv1.0.0Jan 3, 2026

TDQS

A3.8/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It discloses the tool returns raw JSON and has a 1095-day max range, but does not cover authentication, rate limits, or side effects. The description adds some behavioral context but is not comprehensive for a tool with no annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences long, front-loaded with purpose, and contains no extraneous words. Every sentence adds value: first sentence states the action and resource, second details return composition. It is properly sized for the tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given no output schema, the description explains return values (total AZM plus breakdown). The two parameters are fully documented in the schema. Minor gap: no explicit differentiation from sibling tools, but overall the description completes the picture for a simple retrieval tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Input schema has 100% coverage with clear descriptions for both parameters. The description adds the 1095-day max range context but does not significantly enhance parameter meaning beyond what the schema already provides. Baseline 3 is appropriate as schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool retrieves raw JSON for Active Zone Minutes time series from Fitbit over a date range. It specifies the resource (AZM time series), action (get), and scope (max 1095 days, breakdown by zones). This effectively distinguishes it from sibling tools like get_activity_timeseries.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for AZM data but provides no explicit guidance on when to use this tool over alternatives. It mentions the 1095-day max constraint but lacks when-not conditions or alternative tool references. Usage is implied rather than explicitly stated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server